Thursday, September 11, 2008

Media Spin and Neural Plasticity

Sometimes, well perhaps more often than not, the comprehension gulf between a scientific publication and the press release about it is immense. Indeed, I cannot think of one instance, including the array of execrable journalism about vaccines and autism that gets it as wrong as the press release of Hensch et al’s paper in Cell, titled: "Experience-Dependent Transfer of Otx2 Homeoprotein into the Visual Cortex Activates Postnatal Plasticity."

The press release, titled, Trigger for Learning waxes lyrical about brain plasticity and learning, extending it to autism with this reference to the lead author Dr Takao Hensch:

“Dr. Hensch said developmental disorders like autism are a result of impaired timing of these learning "windows," like the one during which children learn to read."

Two things are notable about this statement and this paper. Primarily, the paper is about the development of vision and we have known for quite some time that there is indeed a ‘window of opportunity’ for the development of vision. The paper is not about learning and as far as I know, there is certainly no ‘window’ for reading and neither is there one for learning in general. With that in mind I asked Dr Hensch if he could verify the article’s depiction of what he said.

Dr Hensch replied with:“Thank you for your question and interest in our work. I apologize for any confusion brought about by the media. What I said was "disorders such as autism, in which researchers believe critical periods may be inappropriately accelerated or delayed." I am unaware of any critical period for reading as you point out.”

Quite likely Dr Hernsch is referring to the accelerated head growth noted in autistic toddlers. This is quite some distance from ‘windows of opportunity’ for learning that the press release implies. It’s a shame in a way because it detracts from the beauty of this work. Science can be truly wonderful, especially at moments like this where a protein, initially responsible for forming the head of the fetus in very early development is recycled to play an important part in the laying down the connections for processing visual information. How cool is that?

Neural plasticity is not well understood as yet but what we do know of it tends to support the notion that the ‘window’ of cognitive development is quite wide and that those promoting ‘early intervention’ on the back of short windows of opportunities for learning are doing so based on no evidence as “The Myth of the First Three Years” makes very clear. As Drs Frith and Blakemore pointed out to a teacher who also hadn’t kept up with her neural development:

“Some parts of the cortex, including the frontal cortex, which is responsible for cognitive functions such as planning, decision making and self awareness, continue to develop during the teenage years and into the twenties.”